Incandescent lamp



y 1959 H. A. ANDERSON 2,886,735

INCANDESCENT LAMP Filed Aug. 4, 1958 INVENTOR. flE/PBEET A. ANDERSON v flTTOfA/EVS INCANDESCENT LAlVIP Herbert A. Anderson, Leonia, N.J., assignor to Duro- Test Corporation, North Bergen, NJ., a corporation of New York Application August 4, 1958, Serial No. 752,$91

1 Claim. (Cl. 313-274) The present invention relates to incandescent lamps and particularly to incandescent lamps for use in what is common y known as rough service.

More particularly still the invention relates to a lamp of the heavy duty or rough service type which is normally burned in a base up position and which is normally a gas-filled lamp as contrasted with a vacuum type lamp.

The lamp of the present invention is constructed with an envelope having a cylindrical domed portion as contrasted with the usual spherical end portion. This domed portion provides a chamber which, during normal base up operation, is at a relatively low temperature despite the fact that the lamp is gas-filled and therefore heat conductive. Due to this cool area the lamp may be more readily removed from its socket when it is to be replaced since a cool area is present which can be gripped.

Moreover, the cylindrically walled domed portion provides a means for resiliently positioning the filament mounting which combines with the resilient mount normally supplied from the press and thereby breaking of the filament or the lead-ins as a result of shock which is to be expected in a lamp used in the service indicated.

It is an object of the invention to provide an incandescent lamp having a bulb or enclosure which is provided with a generally cylindrical extension forming a dome.

It is another object of the invention to utilize the domed cylindrical side walled portion of the enclosure as a bearing surface against which resilient arms extending from the filament support may rest to thus provide additional resilient support for the filament mounting.

It is a further object of the invention to provide, by means of the shape mentioned, a cool area which makes it possible to handle the lamp immediately after failure thereof or, in fact, when the lamp is still in operative condition in the event that a change of lamps is desired.

It is a further object of the invention to provide a lamp of the type previously described in which the generally cylindrical side walls are ribbed whereby a finger gripping portion is presented.

Other objects and features of the invention will be apparent when the following description is considered in connection with the annexed drawings, in which,

Figure l is a side elevational view of the lamp of the present invention, the enclosure being broken away to show the resilient arms which aid in positioning the filament mount;

Figure 2 is an enlarged view showing the supporting members for the filament;

Figure 3 is a transverse cross-sectional view taken on the plane of the line 33 of Fig. 1, illustrating particularly the construction of the resilient axial filament guiding means;

Figure 4 is a side elevational view of the lamp of Figure 1 showing a modified form thereof in which the 2,836,735 Patented May 12, 1959 domed portion has polygonal side walls which provide a finger gripping area; and

Figure 5 is a transverse cross-sectional view of the lamp of Figure 4, the view being taken on the plane of the line 5-5 of that figure. This view illustrates the mounting of the resilient arms within the polygonal dome.

The rough service lamp of this invention is a lamp of rugged construction adapted to various uses which normally require a more rugged lamp than the type usually used in the lighting of homes. A rough service lamp in the sense herein disclosed is a lamp sufliciently rugged to withstand the shocks normally incident to use in factories, street lighting, trouble lamps, institutional lighting, and the like. In such use incandescent lamps are as a normal incident thereof, not infrequently subjected to rough handling, shock and the like, for which the usual incandescent lamp construction is not adequate.

Referring now to the drawings, there is shown at 10 the lamp enclosure which is in the usual manner provided with a re-entrant stem and press 11 in which lead in wires 12 are sealed. Also sealed in the press 11 is a longitudinally rigid and transversely flexible resilient supporting member 13, such as the wire shown in Fig. l, which, at its lower end, as seen in Figure 1, carries a rod 14. Sealed in the rod 14 are the upper filament supports 15 and the lower filament supports 16. In the usual manner the filament 17 is strung on the ends of the supports 15 and 16 in a zigzag fashion, the filament being connected at its ends 18 to the lead in wires 12.

In my new lamp the lower end of the enclosure 10, instead of being spherical, is provided with the dome 20 which has the straight side wall portions 21 and the generally spherical end wall 22. As will be readily seen by reference to Figure 1, this dome portion 20 supplies a pocket which is relatively remote from the filament 17 and which therefore remains relatively cool. As a result when it is desired to remove the lamp from its socket the side wall portions 21 may readily be gripped by the fingers and the removal operation performed without danger of burning the fingers and with considerable ease. Not only is this area cooler than would otherwise be the case, but the cylindrical side wall portion 21 forms a finger grippable portion which is not true of the usual lamp in which the contour is completely spherical as indicated by the dotted lines 23, Figure 1.

Moreover, I utilize the domed portion 211) of the envelope 10 to supply an additional supporting member for the filament mount 14. Sealed or otherwise fixed to the glass rod 14 is a resilient metal piece 24 which branches into a number of curved arms 25 at its lower end. These arms 25 rest against the side wall 21 of the dome 20 and thus prevent undue movement of the filament mount and filament if the lamp is dropped or has a shock otherwise imparted to it.

It will be seen that in the service for which these lamps are intended this is an important advantage since in the usual lamp the resilient member 13 may be set into oscillation by shock causing either rupture of the filament 17 or, in some instances, breakage of the lead ins 12 or even breaking of the press where the lead in wires go through the press.

In Figures 4 and 5 I have illustrated a modification of the lamp of Figure 1 in which the side wall of the dome portion 20, instead of being cylindrical, is in the shape of a polygon having the sides 26. As will be appreciated, this enhances the ease with which the domed portion may be gripped for removal or replacement of the lamp.

Additionally, by making the dome with a polygonal asaegrss =3 side Wall the arms 25 may be definitely located in the corners 27, thus further enhancing the positioning of the resilient support 24.

While I have described preferred embodiments of my invention it will be understood that I wish to be limited not by theforegoing description, but solely by the claim granted to me.

What is claimed-is:

In an incandescent lamp combination a sealed glass enclosure having a re-entrant stern, said envelope having a neck portion at one end, a spherical intermediate portion and a domed portion at the other end, said spherical portion being of greater diameter than saidneck and domed portions, a filament assembly, a longitudinally rigid and transversely resilient member attached to said stem at one end and to said assembly at the other end, and a resilient support member" secured to said assembly at'one end and seated in said 'doornedportion to dampen transverse movements of said resilient member, said, assembly comprising an insulating rod, a plurality of support Wires each mounted at one end in said rod and extending radially thereof in a pair of spaced parallel lanes, and a filament supported on the ends of said Wires and forming a cylindrical pattern With said rod, said rod being mounted on the end of said resilient member.

References Cited in the file of this patent UNITED STATES PATENTS 248,407 Crosby et a1. Oct. 18, 1881 896,092 Druseidt Aug. 18, 1908 980,703 Thompson Jan. 3, 1911 1,038,613 Ludecke Sept. 17, 1912 2,173,261 Marden Sept. 19, 1939 2,214,143 May Sept. 10, 1940 2,671,183 St. Louis et al Mar. 2, 1954 2,687,471 Buckingham Aug. 24, 1954 2,688,711 Camillerapp Sept. 1, 1954 2,838,713 Macksoud June 10, 1958 

